OBJECTIVES: The aim of the research project is to study myocardial edema occurring secondary to the ischemic injury. The study aims to define the cause, location, physiologic effect, time course, and treatment of myocardial edema with oncotic and osmotic agents for the purpose of preventing such edema from occurring and reversing it when it does occur. The experiments will investigate the etiology of poor post-operative myocardial performance due to impaired myocardial contractility, and due to altered myocardial compliance due to tissue edema. Localization of the excess tissue water will be determined as intracellular or extracellular by a radioisotope techniques. The role of cardioplegic agents in the genesis and/or amelioration of myocardial edema will be studied.